Who is Anna (Anja) Spiegelman nee Zylberberg from The Complete Maus and what is their importance?

Anja is born March 15, 1912, to Mr. and Matka Zylberberg a very affluent family living in Sosnowiec, Poland. She remains in Sosnowiec until being introduced to Vladek Spiegelman by her cousin. She immediately pursues Vladek and they quickly develop a strong romantic relationship and are married on February 14, 1937.

After Vladek is drafted on August 24, 1939, Anja moves back to Sosnowiec and lives there with her parents until being deported to a Jewish ghetto by the Nazis. Anna and Vladek live in various Jewish ghettos until attempting an escape to Hungary when they are handed over to the Nazis by double-crossing smugglers. Vladek and Anja are then transported to various work camps and on to Auschwitz where they are separated.

Anja survives Auschwitz until she is evacuated from Auschwitz to Ravensbrück where she survives several more weeks of Holocaust until the war finally ends. She then makes her way back to Sosnowiec where she lives with the few surviving members of her family until being reunited with Vladek, after which, they emigrate to Sweden, before making their final move to the United States.